Pressure responsive multiple input infusion system

ABSTRACT

An infusion system for administering multiple infusates at individually programmable rates, volumes, and sequences in any order from any one or more of plural fluid input ports through a patient output port and into the circulatory system of a patient. Infusates may be either continuously or time sequentially administered, and infusates may be either intermittently administered at selectively regular intervals or in time overlap to administer a dilution. Various error conditions are automatically detected and alarms generated in the event of conflicts between infusates, to identify times of no infusions, and to identify system malfunctions. The system is selectively operable, among others, in a priming mode, a maintenance mode, a normal-on mode, and a manual override mode. The system is operative to adapt actual to desired flow rates in normal operation. All fluids flow through a unitary disposable cassette without making any other system contact. Air bubbles in the fluid line are automatically detected and disposed of. Fluid pressures are monitored and system operation adjusted as a function of such pressures. Infusates may be administered from syringes as well as from standard bag or bottle containers. Infusate from a selected input port may be controllably pumped into a syringe for unsticking the syringe plunger. The system is selectively operable to adjust total fluid volume and rate to below preselected values for patients whose total intake must be restricted. The system is operable to maintain an accurate record of total infusion history.

This application is a continuation of application Ser. No. 07/382,719,filed Jul. 19, 1989, now abandoned, which is a continuation of Ser. No.07/355,035, filed May 16, 1989, which is a continuation of Ser. No.07/062,064, filed Jun. 11, 1987, now abandoned, which is a division ofSer. No. 06/873,478, filed Jun. 11, 1986, now U.S. Pat. No. 4,696,671,which is a continuation of Ser. No. 06/578,180, filed Feb. 8, 1984, nowabandoned, and this application is related to Ser. No. 07/039,154, nowU.S. Pat. No. 4,828,545, which is also a division of U.S. Pat. No.4,696,671.

FIELD OF THE INVENTION

This invention is directed to the field of surgery, and moreparticularly, to a novel infusion system having plural fluid input portsand at least one patient output port.

BACKGROUND OF THE INVENTION

Intravenous infusion therapy is prescribed where it is desirable toadminister medications and other fluids directly into the circulatorysystem of a patient. It is estimated that approximately forty percent ofU.S. hospital patients presently receive some form of infusion therapyand it is expected that the proportion will grow in the future due tothe improved health care that results from such therapy.

For many clinical procedures, it is desirable to intravenouslyadminister several fluids to a patient. Plural independent gravity flowcontrollers and plural independent electronic pumps have heretofore beenemployed for this purpose. The plural gravity flow controllers, however,are disadvantageous, among other things, due to the increasedpossibility of infection occasioned by multiple IV venipuncture; due tothe flow inaccuracies occasioned, among other things, by patientmovement induced tube occlusion or tubing shape changes; due to theconsiderable labor and time required from a nurse or other healthpractioner to manually control the plural gravity flow controllers inaccordance with a prescribed course of therapy; due to clutter aroundthe patient; and due to the possibility of out-of-control infusionoccasioned by a failure of one or more of the gravity flow controllers.The plural independent pumps are disadvantageous, among other things,due to the clutter around the patient occasioned by the use of pluralpumps; due to the increased possibility of infection occasioned bymultiple IV venipuncture; due to the comparatively high cost ofprocuring and maintaining several pumps for each such patient; due tothe incapability of the heretofore known pumps to administer more thantwo infusates in time sequence without additional pumps; due to theincapability of the heretofore known pumps to administer dilutions; dueto the considerable time and labor required by the health practitionerto program and to supervise the plural independent pumps; and due to thecomparatively high cost incurred in maintaining an inventory of tubesand administration sets that must be replaced periodically to avoidinfection for each pump, fluid, and patient, often amounting on anannual basis to about one half the cost of the pumps themselves.

SUMMARY OF THE INVENTION

The novel infusion system of the present invention contemplates meansoperable to controllably infuse preselected fluids from any one or moreof plural fluid input ports either simultaneously or in time sequencethrough at least one patient output port and into the circulatory systemof a patient in a predetermined time sequence. Infusates may beadministered from bag or bottle containers or from syringes. A smallquantity of fluid may be pumped into the syringe to unstick the syringeplunger. The infusion system of the present invention is operative toidentify potentially conflicting infusions and to alert the systemoperator. The system operator may, among other things, either rescheduleconflicting infusions or select an alarm and automatic shutdown prior tothe time when conflicting infusions are scheduled to commence. Theinfusion system of the present invention is operative to administernonconflicting infusions at the same rate or different rates to provideeither mixing of the infusates or dilution of the concentration of oneof the infusates.

The infusion system of the present invention is selectively operative ina maintenance mode to controllably administer a fluid from a preselectedfluid input port to keep the vein of a patient open at such times whenselected fluids are not being infused in accordance with a particularcourse of infusion therapy.

The infusion system is selectively operable in a priming mode to ventfluid and air from a selected fluid input port to prevent possible airembolism.

The infusion system is selectively operable in a manually initiatedoverride mode to controllably administer any one or more of pluralfluids during emergency or other situations.

The infusion system having plural fluid input ports and at least onepatient output port of the present invention in preferred embodimentincludes a processor. A memory is operatively coupled to the processor.Means coupled to the processor are provided for entering into the memorydata representative both of the desired time sequence for and of adesired rate of flow of each of any one of a plurality of fluids to beinfused in any order. A plurality of input valves are operativelyconnected to the processor for accessing the flow of a corresponding oneof the fluid inputs. An output valve is operatively connected to theprocessor for controlling the fluid flow out of the output port. Apumping chamber is operatively connected to the processor and is influid communication with each of the input valves and the output valvealong a common fluid flow path. Means coupled to the processor andresponsive to the data are provided for repetitively actuating the inputvalves and concurrently expanding the pumping chamber in a time sequenceselected to fill the pumping chamber with the corresponding fluid to beinfused and for repetitively actuating the output valve and concurrentlycontracting the pumping chamber at a rate selected to infuse thecorresponding fluid through the patient output line at the desired rate.The data entry means includes an operator interactive display and akeyboard. The processor includes a main control processor and a pumpcontrol processor slaved to the main control processor. The main controlprocessor is operative to provide operator prompts on the operatorinteractive display, to provide system status information on thedisplay, and to provide one of plural display templates representativeof desired pumping mode and sequence. The pump control processorexecutes instructions representative of the desired pumping sequence andmode that are down loaded thereto by the main control processor forexecution, generates and reports various error and alarm conditions tothe main control processor, and generates several alarms including airin line, patient occlusion, and empty bottle. The pumping chamber andthe input and output valves are provided in a sterile, disposable,cassette injection-molded out of biologically inert medical-gradeplastic. The cassette includes a longitudinally extending channel influid communication with the pumping chamber, a pressure chamber, aplurality of fluid input ports, a patient output port, and a vent port.The cassette in preferred embodiment consists of a two part semi-rigidhousing and a flexible diaphragm consisting of silicone rubber that issandwiched between the two parts of the housing. The diaphragm includesa plurality of resilient valve stops that individually project into acorresponding one of the fluid input ports, output port, and vent port,and includes a flexible drum that extends over the pressure chamber anda dome that extends over the pumping chamber. The cassette is orientedpreferably at a forty-five degree angle to the vertical with the ventport and pressure chamber above the pumping chamber. Any slight quantityof air in the fluid flow path rises above the pumping chamber and intothe pressure chamber thereby preventing the possibility of air passingto the patient. A stepper-motor controlled cam drives a correspondingspring-biased plunger associated with each input fluid port and theoutput port for controlling the state of actuation of its associatedresilient stop. The input and output port plungers are so driven thatthe patient output port is in a closed state whenever any one of thefluid input ports are in an open state and are so driven that all of theinput ports are closed whenever the output is open, to preventunintended gravity flow infusion. A stepper-motor controlled cam strokesa pumping piston associated with the pumping chamber to expand orcontract the pumping chamber for filling or expelling fluid therefrom. Apressure transducer is coupled to the pressure chamber and operativelyconnected to the pump controller for providing pressure data during eachpumping piston stroke representative of air-in-line, bottle headpressure, downstream occlusion, and of variation between actual andintended infusate volume. The system responds to the pressure data tovent fluid and air from the line and to adjust operation in a pressuredependent manner. The system is selectively operable in a controlledmode to allow fluid to flow from any selected fluid input to a selectedoutput under gravity control without actuating the pumping pistonwhenever desirable.

BRIEF DESCRIPTION OF THE DRAWINGS

Other features and advantageous of the present invention will becomeapparent as the invention becomes better understood by referring to thefollowing exemplary and non-limiting detailed description of thepreferred embodiment, and to the drawings, wherein:

FIG. 1 is a block diagram illustrating the novel infusion system havingplural fluid input ports and at least one patient output port accordingto the present invention;

FIG. 2 is a state diagram illustrating the operating states of theinfusion system having plural fluid input ports and at least one patientoutput port according to the present invention;

FIG. 3 illustrates in FIG. 3A an isometric view of a preferredembodiment of a housing for, and illustrates in FIG. 3B a plan view of apreferred embodiment of a control panel for, the infusion system havingplural fluid input ports and at least one patient output port accordingto the present invention;

FIG. 4A is a plan view illustrating one portion of a cassette of theinfusion system having plural fluid input ports and at least one patientoutput port according to the present invention;

FIG. 4B is a plan view illustrating another portion of the cassette ofthe infusion system having plural fluid input ports and at least onepatient output port according to the present invention;

FIG. 4C is a plan view illustrating a flexible diaphragm of the cassetteof the infusion system having plural fluid input ports and at least onepatient output port according to the present invention;

FIGS. 4D and 4E are sectional views of the cassette taken along thelines D--D and E--E of FIGS. 4A-4C of the infusion system having pluralfluid inport ports and at least one patient output port according to thepresent invention;

FIG. 5 is a partially exploded perspective view with the cover removedof a valve and pumping actuator of the infusion system having pluralfluid input ports and at least one patient output port according to thepresent invention;

FIG. 6 is a side view of the valve and pumping actuator illustratingrotary position sensors of the infusion system having plural fluid inputports and at least one patient output port according to the presentinvention;

FIG. 7 is a rolled out view illustrating a position sensor for the valveactuator of the infusion system having plural fluid input ports and atleast one patient output port according to the present invention;

FIG. 8 is a rolled out view illustrating a position sensor for thepumping actuator of the infusion system having plural fluid input portsand at least one patient output port according to the present invention;

FIG. 9 is a rolled out view illustrating the operation of the valve andpumping actuator and position sensors of the infusion system havingplural fluid input ports and at least one patient output port accordingto the present invention;

FIG. 10 is a schematic diagram of the system controller of the infusionsystem having plural fluid input ports and at least one patient outputport according to the present invention;

FIG. 11 is a diagram illustrating a data file of the main controlprocessor of the infusion system having plural fluid input ports and atleast one patient output port according to the present invention;

FIG. 12 is a diagram illustrating an instruction byte of the maincontrol processor of the infusion system having plural fluid input portsand at least one patient output port according to the present invention;

FIG. 13 illustrates in FIG. 13A a status byte of the pump controlprocessor and in FIG. 13B a communications protocol between the maincontrol processor and the pump control processor of the infusion systemhaving plural fluid input ports and at least one patient output portaccording to the present invention;

FIG. 14 illustrates the command bytes of the main control processor ofthe infusion system having plural fluid input ports and at least onepatient output port according to the present invention;

FIG. 15 illustrates the data bytes of the pump control processor of theinfusion system having plural fluid input ports and at least one patientoutput port according to the present invention;

FIG. 16 is a data flow chart illustrating the operation of the infusionsystem having plural patient input ports and at least one patient outputport according to the present invention;

FIG. 17 is a flow chart illustrating the operation of the main controlprocessor of the infusion system having plural fluid input ports and atleast one patient output port according to the present invention;

FIG. 18 is a flow chart illustrating one pumping sequence of the pumpcontrol processor of the infusion system having plural fluid input portsand at least one patient output port according to the present invention;

FIG. 19 is a flow chart illustrating another pumping sequence of thepump control processor of the infusion system having plural fluid inputports and at least one patient output port according to the presentinvention;

FIG. 20 is a flow chart illustrating another pumping sequence of thepump control processor of the infusion system having plural fluid inputports and at least one patient output port according to the presentinvention;

FIG. 21 is a flow chart illustrating another pumping sequence of thepump control processor of the infusion system having plural fluid inputports and at least one patient output port according to the presentinvention;

FIG. 22 is a flow chart illustrating another pumping sequence of pumpcontrol processor of the infusion system having plural fluid input portsand at least one patient output port according to the present invention;and

FIG. 23 is a diagram illustrating an exemplary operating sequence of theinfusion system having plural fluid input ports and at least one patientoutput port according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to FIG. 1, generally designated at 10 is a block diagramof the novel infusion system having plural fluid input ports and atleast one patient output port according to the present invention. Thesystem 10 includes a disposable cassette generally designated 12 to bedescribed having a fluid channel 14. A plurality of fluid input ports16, four (designated "A", "B", "C", and "D") being specificallyillustrated, are connected to the fluid flow channel 14 through acorresponding one of a plurality of valves 18. Each fluid input port 16is directly connectable to a selected fluid to be infused, not shown.The cassette 12 includes a pumping chamber generally designated 20connected to the fluid channel 14, and a pressure chamber generallydesignated 22 connected to the pumping chamber 20 via a fluid flowchannel 24. A patient output port 26 is connected in a fluid flow pathto the pressure chamber 22 via a valve 28, and a vent output port 30 isconnected to the pressure chamber 22 in a fluid flow path via a valve32. The patient output port 26 is directly connectable to a patient viaa patient output line, not shown. The vent output port 30 is directlyconnectable, for example, to a collection bag to be described or otherfluid sink.

An input and output valve actuator 34 to be described is operativelyconnected to the plural fluid input valves 18 and to the patient outputvalve 28. The actuator 34 is operative to select the "open" and the"closed" state of the valves 18, 28, and therewith to control fluid flowfrom the corresponding fluid input ports 16 into the cassette 12 and tocontrol fluid flow out of the cassette into the patient. The actuator 34is preferably operative to prevent the input and output valves frombeing simultaneously in the "open" condition to eliminate thepossibility of unintended gravity flow infusion. A separate actuator tobe described is preferably connected to the output valve 28 to maintainthe patient output port and any selected input port "open".

A vent valve actuator 36 to be described is operatively connected to thevent valve 32. The actuator 36 is operative to select the "open" and the"closed" state of the valve 32, and therewith to control fluid flow fromthe cassette 12 into the collection bag to remove air from the fluidflow channel during initial setup and during operation of the infusionsystem.

A cassette-locked-in-place sensor 38 is operative to provide a signalthat represents that the cassette is in its intended operating positionto prevent fluid leakage and unintended infusion.

A pressure transducer 40 to be described is operatively connected to thepressure chamber 22. The pressure transducer 40 is operative to providean analog signal representative of the pressure in the pressure chamber22. An amplifier 42 amplifies the analog signal, and an analog todigital converter (ADC) 44 converts the amplified analog signal intodigital data. During preselected stages of a pumping sequence to bedescribed, the digital data provides information representative of airin line, of actual infusion volume relative to nominal infusion volume,of patient output line occlusion, and of fluid level remaining to beinfused through corresponding fluid input ports 16.

A pumping actuator 46 to be described is operatively connected to thepump chamber 20. The pumping actuator 46 is operative to controllablyfill and pump fluid from the pumping chamber 20 into either the patientoutput port 26 or the vent output port 30 in dependence on the state ofactuation of the valves 28 and 32. The pumping actuator 46 is operativeto precisely administer an intended amount of fluid in an intended timeinterval from any one or more of the fluid input ports 16 in any ordereither in time sequence or in time overlap to dilute the concentrationof a selected infusate.

A system controller generally designated 48 to be described isoperatively connected to the input and output valve actuator 34, to thevent valve actuator 36, to the cassette-locked-in-place sensor 38, tothe analog to digital converter 44, and to the pumping actuator 46. Thesystem controller 48 is operative to provide control signals to theactuator 34 to "open" and "close" the valves 18 in an intended timesequence, to provide control signals to the actuator 46 to pump thechamber 20 at a rate selected to administer a preselected volume ofinfusate during a prescribed time interval, and to provide controlsignals to the actuator 36 to eliminate air from the fluid flow pathduring set-up and during infusion.

An operator interactive display 50 is operatively connected to thesystem controller 48. The display 50 is operative to display one ofplural display templates to be described that individually correspond tothe modes of operation of the system controller 48, to display systemstatus information, to display operator prompts to assist the operatorin selecting volume, rate, and time of infusion, and to display variouserror and alarm conditions. The modes includes a flush mode template, aprime mode template, an override mode template, a primary mode template,and a piggyback mode template.

Operator data and function keys 52 to be described are operativelyconnected to the system controller 48. The data and function keys 52 areoperative for selecting the rate, volume, and time of infusion; forselecting the state of operation of the infusion system including theoverride mode, the priming mode, and the normal-on mode; for controllingthe operator interactive display; and for selecting maximum occlusionpressure, minimum infusion rate, and total fluid volume to beadministered.

Status light emitting diodes (LED's) 54 are operatively connected to thesystem controller 48. The LED's 54 are operative to provide a visualindication of the various alarm conditions and of battery status. Anaudible alarm 56 is operatively connected to the system controller 48 toprovide an audible indication of alarm condition. One or more slaveinterfaces 58 are operatively connected to the system controller 48.Each slave interface 58 is connectable to an auxiliary pump to bedescribed that may be slaved to the system controller 48 to administerthe infusion of an incompatible infusate. A universal asynchronousreceiver transmitter interface (UART) 60 is operatively connected to thesystem controller 48. The UART 60 may be connected to any suitableperipheral device such as a display terminal or a computerized centralnurse station.

A rectifier and regulator 62 is connected to a source of AC power 64such as a conventional hospital outlet via a fusible link 66. Aregulator 67 is connected to the rectifier and regulator 62 via a switch70. The rectifier and regulator 62 and regulator 67 provide power to theinfusion system in normal operation. A battery 68 provides power to theinfusion system either in the event of a power failure or in the eventthat it is desirable to move the patient such as between an intensivecare unit and an operating room. The battery 68, the rectifier andregulator 62, and regulator 67 are operatively connected to the ADC 44designated "Voltage Inputs". The system controller 48 is operative inresponse to a fall in the output of the converter signal from theregulators below a predetermined value to switch to the battery 68, andthe controller 48 is operative to activate a corresponding status LED toprovide a low battery indication whenever the level of the battery fallsbelow a predetermined level.

Referring now to FIG. 2, generally designated at 72 is state diagramillustrating the principal operating states of the system controller 48(FIG. 1). In an "off" state 74, the system controller 48 is waiting, itsclock is running, and no pumping is occurring. In a "programming" state76, data is selectably input to specify the time, rate, and volume forfluid to be administered from any one or more of the plural fluid inputports 16 (FIG. 1), and data is selectably input to specify current time,KVO rate, maximum occlusion pressure, and total fluid rate and volume.Data entered is selectably displayable in the "programming" state on theoperator interactive display for operator review. In an "override" state78, the system controller 48 (FIG. 1) is operative in a manual overridemode. In the state 78, data is selectably input to specify an emergencyinfusion rate from a selected one of the plural fluid input ports and topump the fluid at the specified emergency rate. In a "priming" state 80,data is selectably input to specify an input line as a priming line. Thesystem controller is operative in the "priming" state to allow fluid toflow by gravity from a selected input port through the cassette 12(FIG. 1) and either into the collection bag to remove air from thecassette or through the output port and into the patient output lineprior to venipuncture to remove air from the patient line. In the"priming" state, fluid may also be primed by pumping. In an "auto-on"state 82, the system controller is operative to automatically pump fluidfrom the input ports at the rates, volumes, and times specified in the"programming" state. The system controller in the "programming" statefor a particular one of the plural fluid input ports may also be in the"auto-on" state 82 for the other ones of the plural fluid input portsthat may be being infused at a selected rate, volume, and time into thepatient in accordance with a desired course of therapy. In a "history"state 84, the system controller is operative to display on the operatorinteractive display data representative of the total quantity of fluidadministered to a patient from the plural fluid input ports at a giventime. Data accumulated in the history state 84 can advantageously beemployed with a computerized hospital information system. In a "slavepump controller" mode 86, the system controller is operative to controlone or more auxiliary pumps. The auxiliary pumps can advantageously beemployed to control one or more additional infusions for theadministration of an incompatible drug without losing the benefit ofintegrated infusion control and data accumulation.

Referring now to FIG. 3A, generally designated at 88 is an isometricview illustrating a preferred embodiment of a housing of the infusionsystem having plural fluid input ports and at least one patient outputport according to the present invention. The housing 88 is mounted to aconventional IV pole 92 such that its front panel generally designated90 to be described is oriented at an angle selected to provide ease ofoperator access, preferably 45°. A disposable cassette generallydesignated 94 to be described is slidably mounted in a channel generallydesignated 96 provided therefor on one side of the housing 88. Thecassette 94 is oriented at the same angle of inclination to the verticalto allow both pumping with slight quantities of air in the fluid flowpath and the expeditious removal of air from the fluid flow path asappears more fully below. A locking lever 100 having a safety mechanism102 to be described is pivotally mounted to the housing 88. The lever100 is operatively connected to a rod to be described that is mountedfor reciprocating motion in the housing 88. By simultaneously releasingthe locking mechanism 102 and pivoting the lever 100, the rod is operateto removably retain the cassette 94 in the channel 96 on the side of thehousing 88 in a manner to be described. The cassette 94 includes fourfluid input ports 104, 106, 108, and 110, a patient output port 112, anda vent output port 114. A plurality of fluid containers are positioned apredetermined vertical distance above the housing 88 and directlyconnected to corresponding of the fluid input ports, two such fluidcontainers 116, 118 connected to the input ports 104, 106 beingspecifically illustrated. It will be appreciated that two additionalfluid containers, bags, or syringes, not shown, may be directlyconnected to the ports 108, 110. A plurality of indicating lines 119 areprovided on the side of the housing. A patient output line 120 isconnected to the output port 112, and a collection bag line 122 isconnected between the vent output port 114 and a collection bagremovably retained on the back of the housing 88, not shown.

Referring now to FIG. 3B, generally designated at 124 is a plan view ofa preferred embodiment of the front panel of the housing of the infusionsystem having plural fluid input ports and at least one patient outputport according to the present invention. The front panel 124 includes anoperator interactive display 126 for displaying one of a plurality ofdisplay templates to be described. The display 126 preferably is an 80character LCD display commerically available, for example, from Epson. Aplurality of display command keys designated by a dashed box 128 areprovided on the front panel 124. The display keys 128 include a clearentry key 130, a last entry key 132, a next entry key 134, and an enterkey 136. The clear entry key 130 when pressed clears inadvertently ormistakenly entered data, the last entry key 132 when pressed moves adisplay cursor to a previous field of a display, the next entry key 134when pressed moves a display cursor to the next field of a display, andthe enter key 136 enters the data entered into the various fields of adisplay into system memory.

A plurality of rate, volume, and time command keys designated by adashed box 138 are provided on the front panel 124. The rate, volume,and time command keys 138 include a primary infusion key 140, apiggyback infusion key 142, a flush key 144, and a reset key 146. Theprimary infusion key 140 when pressed selects the programming state 76(FIG. 2), and displays a primary infusion template for each fluid inputthat allows selection of the rate, volume, and time sequence of infusionfrom any one or more of the plural fluid input ports in any order toimplement a prescribed course of therapy that calls for thenonsimultaneous infusion of primary fluids at the same or differentrates in a predetermined time sequence. The primary infusion templatepreferably has the following format. ##STR1##

The operator then presses any one of keys 162, 160, 166, 168 to bedescribed. If the operator selects the key 168, designated "A", forexample, an "A" appears in the first data field of the primary infusiontemplate. The operator then presses the "next" key 134 and the displaycursor moves to the second data field of the infusion primary template.The operator then selects either a key 176 or a key 178 to be describedand a "yes" or a "no" appears in the second data field of the template.Call back when selected by pressing the "yes" key 176 specifies that thesystem operator is to be called back prior to beginning infusion on theselected line. The operator then presses the "next" key 136 again andthe system controller is operative to display the following displaytemplate. ##STR2##

The operator then presses the appropriate data keys 170 to be describedand appropriate display command keys 128 to enter a selected rate,volume, duration of fluid to be administered, and container volume forprimary line "A". The data fields of the templates are shown herein byeither "dashed" underline or by "solid" underline. "Dashed" underlineentry is optional. For example, if rate and volume are specified for theabove template, the system controller can calculate duration and volume.The operator then presses the "enter" key 136, and the selected data isentered into the corresponding addresses of a data file to be describedfor that line. The above process may be repeated for selecting the rate,volume, and time for lines B, C, and D as primary lines.

The piggyback infusion key 142, when pressed, selects the "programming"state 76 (FIG. 2) and displays a piggyback infusion template that allowsselection of the rate, volume, and time sequence from any one or more ofthe plural fluid input ports in any order to implement a course oftherapy that calls for the intermittent infusion of one or morepiggyback fluids either at regular repeat intervals or in time overlapto provide a dilution of the concentration of one of the infusates.Piggyback infusions are each preferably less than sixty minutes induration. The piggyback infusion template preferably has the followingformat. ##STR3##

The operator then presses any of keys 162, 164, 166, 168. If theoperator selects the key 166, designated "B", for example, a "B" appearsin the first data field of the piggyback infusion template. The operatorthen presses the "next" key 134 and the display cursor moves to thesecond data field of the piggyback infusion template. The operator thenselects either the key 176 or the key 178 and a "yes" or a "no" appearsin the second data field of the template. Call back again selects orcalls back the operator before infusion on line "B". The operator thenpresses the "next" key 136 and the display cursor then moves to thethird data field of the piggyback infusion template. The operator thenselects either the key 176 or the key 178 and a "yes" or a "no" appearsin the third data field of the template. Syringe when selected specifiesa pumping sequence to unstick the syringe plunger from a preselectedfluid input port in a manner to be described. The operator then pressesthe "next" key 136 again and the system controller is operative todisplay the following display template. ##STR4##

The first data field allows the operator to select rate, the second datafield allows the operator to select volume, the third data field allowsthe operator to select duration in minutes, the fourth data fielddesignated "Q" allows the operator to select repeat interval, and thefifth data field designated "X" allows the operator to select the numberof times the same infusion is to be repeated. It is noted that therepeat interval for this template is optional. After entering the datainto the data fields and pressing the "next" key, the system controlleris then operative to display the following display template. ##STR5##

The first data field allows the operator to specify the volume of thefluid container for the "B" line, the second data field allows theoperator to select a fluid input line for dilution, the third data fieldallows the operator to select diluent volume, and the fourth data fieldallows the operator to select diluent rate. The operator then pressesthe "enter" key 136 and the data is written into the correspondingaddress locations of the data file for that line.

The flush key 144 when pressed is operative to allow the selection ofone of the plural fluid input ports as a flushing line for buffering oneinfusate from another and to allow the selection of a variable flushquantity and rate selected to accommodate different lengths of thepatient output line 120 (FIG. 3A). The flush display template preferablyhas the following format. ##STR6##

The operator then presses a selected key 162, 164, 166, 168 to specifythe flush line for the first data field, and the appropriate keys 170 tospecify the rate and volume of flush for the second and third datafields. The operator then presses the "enter" key and the data isentered into the data file. During flushing, the system controller isoperative to display the following display template. ##STR7##

The reset key 146 when pressed allows the operator to clear a previousrate, time, and volume selection for each of the plural fluid inputports. If an infusion is in process when this key is pressed, the systemcontroller is operative to display on the operator interactive display128 the following display template to prompt the operator to insure thatthe key has not accidently been pressed. ##STR8##

A plurality of pump command keys designated by a dashed box 148 areprovided on the front panel 124. The pump command keys 148 include astart key 150, a stop key 152, an override key 154, and a priming key156. The start key 150 when pressed is operative to initiate a selectedcourse of infusion therapy. The system controller is operative todisplay the following template if the start key 150 is pressed for aprimary line. ##STR9##

The first and second data fields of the start primary display templateallows operator selection of the starting time of the selected line inmachine time, the third and fourth data field allows operator selectionof a specified time delay start, and the fifth data field allowsoperator selection of a start of the designated primary line aftertermination of infusion on another line. The operator then presses the"enter" key and the selected data is written into the data file addresslocations for that line.

The system controller is operative to display the following displaytemplate if the start key 150 is pressed for a piggyback line. ##STR10##

The first data field allows operator selection of the line. The secondand the third data fields (hours, minutes) allow operator selection of aspecified starting time. The fourth and fifth data fields allow operatorselection of specified time delay start before the selected line isstarted. If no data is entered there, pumping starts at current systemtime. The operator then presses the "enter" key and the selected data iswritten into the data field address locations for that line.

The stop key 152 when pressed is operative to terminate the desiredcourse of infusion. The system controller is operative to display thefollowing display template to ensure an intended stop. ##STR11## Thedata field for the display template allows operator selection of theappropriate line to be stopped, which, when entered, is written to thedata file.

The override key 154 when pressed is operative to select the overridestate 78 (FIG. 2). The override key 154 stops all previously selectedinfusion parameters and allows the operator to select any one of thefluid input ports at a selected rate for infusion during emergency orother situations. The system controller is operative to display thefollowing template when the key 154 is pressed. ##STR12##

The first data field allows operation selection of the override line,and the second data field allows operator selection of the overriderate. The display template advises the operator with a prompt that allpreviously selected rates, lines, and volumes are no longer in effect.

The prime key 156 when pressed selects the priming state 80 (FIG. 2).The priming key 156 allows the operator to select any one of the fluidinput ports to allow fluid to flow from the selected port through thecassette and into either the collection bag or patient output line. Thecorresponding valves are held open allowing fluid to flow as long as theselected line key is held down. The system controller is operative todisplay the following display template when the prime key is pressed.##STR13## The first data field allows the system operator to selectwhich input port is to be primed into the collection bag. The systemcontroller is operative to continue the priming action from the selectedline so long as the corresponding one of the keys 162, 164, 166, and 168is manually maintained in a closed condition.

If the system operator presses the key 160 after pressing the prime key,the system controller is operative to display the following displaytemplate. ##STR14## The first data field of the template allows theoperator to select which input port is to be primed into the patientline. The system controller is operative to prime the patient line aslong as the corresponding key 162, 164, 166, and 168 is held down.

A plurality of fluid input and output port control keys designated by adashed box 158 are provided on the front panel 124. The input and outputline selection keys 158 include a patient line key 160, a "D" input portselection key 162, a "C" input port selection key 164, a "B" input portselection key 166, and an "A" input port selection key 168. As describedabove, pressing the prime key 156 followed by pressing the patient linekey 160 and with the selected line key held down, selects priming fromthe selected fluid input port through the cassette and into the patientoutput line so long as the selected line key is held down. Pressing thepriming key followed by pressing any one of the keys 162, 164, 166, and168 selects priming from the selected fluid input port through thecassette and into the collection bag. As described above, pressing theoverride key 154 and any one of the keys 162, 164, 166, and 168 selectsoperation in the override mode for the selected line. The keys 162, 164,166, 168 are similarly operative when the primary infusion key 140, thepiggyback key 142, and the flush key 144 are pressed.

If any one of the keys 162, 164, 166, 168 is pressed alone (that is,when not in combination with any key described above), the systemcontroller is operative to display the status of the corresponding fluidinput port using either a primary line or a piggyback line statusdisplay template. The primary line status display template preferablyhas the following format. ##STR15## The piggyback line status displaytemplate preferably has the following format. ##STR16##

If the key 160 is pressed alone (that is when not in combination withany key described above), the system controller is operative to displaya patient line status template. The patient line status templatepreferably has the following format. ##STR17## The first data fielddisplays occlusion pressure, the second data field displays maximumrate, the third data field displays patient line pressure, and thefourth data field displays keep vein open (KVO) rate.

A plurality of data keys designated by a dashed box 170 are provided onthe front panel 124. The data keys 170 include numeric keys "1" through"9" for entering the appropriate infusion parameters including rate,volume, and time for each of the plural fluid input ports, "AM" and "PM"keys to select the corresponding time periods, and "yes" and "no" keys176, 178 to allow the operator to select among the operator promptsdisplayed in the various display templates on the operator interactivedisplay 126.

An IV flow sheet key 180 is provided on the front panel 124. The key 180when pressed is operative to select the history state 84 (FIG. 2). Whenthe key 180 is pressed, the system controller is operative to displayup-to-date total infusion volume. The system controller is operative todisplay the following display template when the key 180 is pressed.##STR18## The data fields of the display template are selectablyresettable by pressing the reset key 146 in the appropriate data field.

An explain key 182 is provided on the front panel 124. The explain key182 when pressed in sequence with any of the function keys describedabove provides an operator display template on the operator interactivedisplay 126 that assists the operator in understanding the function ofthe corresponding key. Each key preferably should be held down withinthree seconds after the explain key is pressed to obtain an explanationof the key. Exemplary display templates are omitted for brevity ofexplication. A mute key 184 is provided on the front panel 124. Thesystem controller is operative when the mute key 184 is pressed tosilence the audible alarm.

A plurality of status LED's designated by a dashed box 186 are providedon the front panel 124. The status LED's 186 include an AC power LED188, a battery LED 190 and an alarm LED 192. The AC power LED 188provides a visual indication that the infusion system is operative underAC power, the battery LED 190 provides a visual indication that theinfusion system is operative under internal battery power, and the alarmLED 186 provides a visual indication of either an alarm condition or anerror condition. The system controller is operative to provide an alarmindication to indicate that infusion is complete on a line, to indicatethat call back has been requested, to indicate an occlusion situation,to indicate air in line, to indicate a low battery condition, toindicate an out of place cassette, and to indicate that primaryinfusions are simultaneously scheduled. The system controller isoperative to display the following display templates for each of thealarm conditions. ##STR19##

The system controller is operative to provide an error indication toindicate pump failure and to indicate an out-of-range entry or invalidkey. The corresponding error display templates preferably have thefollowing formats. ##STR20##

The system controller is operative to display the following "home"display template indicating system status whenever it does not displayany of the above described display templates. ##STR21##

The states for each of the lines will be either "OFF", "PGM", "ON","OVR", or "KVO". "OFF" indicates that the corresponding line is in aninactive state; "PGM" indicates that the corresponding line has beenprogrammed to pump at a selected rate, volume, and time; "ON" indicatesthat the corresponding line is pumping; "OVR" indicates that thecorresponding line is in the override state; and "KVO" indicates thatthe corresponding line is in a keep vein open mode.

Additional display templates to set current time, to select maximumocclusion pressure, to select maximum infusion rate, and to select akeep-vein-open mode and rate are displayed by pressing the "*" key 174followed by a corresponding data key "1", "2", "3", and "4". Thesedisplay templates preferably have the following format. ##STR22## Theoperator then presses the "enter" key and the selected data is enterredinto the corresponding address locations provided therefor in the datafile for each display template.

Referring now to FIG. 4, generally illustrated at 194 in FIG. 4A is afirst housing portion, generally designated at 196 in FIG. 4B is asecond housing portion, and generally designated at 198 in FIG. 4C is aflexible diaphragm of a disposable cassette of the infusion systemhaving plural fluid input ports and at least one patient output portaccording to the present invention. As shown in FIG. 4A, the housingportion 194 includes an injection molded clear plastic member 200 thatmeets appropriate U.S. Pharmacopia standards. The member 200 includes anintegral upstanding peripheral flange 202 and a longitudinally extendingfluid flow channel 204. A plurality of longitudinally spaced fluid inputapertures generally designated 206 and a pumping chamber generallydesignated 208 are integrally formed with the member 200 incommunication with the fluid flow path channel 204. A channel 210 isintegrally formed with the plastic material 200 between the pumpingchamber 208 and a pressure chamber generally designated 212. The chamber212 is integrally formed with the plastic material 200. A patient outputaperture generally designated 214 and a vent output aperture generallydesignated 216 are integrally formed with the plastic material 200 andare in fluid communication with the pressure chamber 212. A disc 218having a central aperture 220 is provided over the pressure chamber 212that cooperates with the walls defining the pressure chamber to preventthe collapse of the diaphragm 198 (FIG. 4C) into the chamber 212. Asbest seen in FIG. 4D, the cassette housing portion 194 includes anannulus 222 defining an input fluid port integrally formed surrounding acorresponding one of the fluid apertures 206, 214, 216 (FIG. 4A).Diametrically opposed locking flanges 224 are integrally formed on theends of each annulus 222. The plastic member 200 includes longitudinallyextending shoulders 225 that abut longitudinally extending guidesprovided therefor on the side of the housing 88 (FIG. 2A) that preventsthe movement of the cassette 94 (FIG. 3A) in a direction transverse toits plane.

Referring now to FIG. 4B, the housing portion 196 includes a clearplastic member 226 that mates in fluid tight sealing engagement with thehousing portion 194 (FIG. 4A). The member 226 includes a longitudinallyextending diaphragm receiving recess 228. A plurality of longitudinallyspaced input valve plunger receiving apertures generally designated 230are provided through the plastic member 226. An output valve plungerreceiving aperture 232 is provided in the plastic member 226 and a ventvalve plunger receiving aperture 234 is provided in the plastic member226. An upstanding annular flange 236 integrally formed with the plasticmember 226 is provided surrounding each of the input valve plungerreceiving apertures 230, the vent valve plunger receiving aperture 234,and the output valve plunger receiving aperture 232. A semicircularchannel portion generally designated 238 integrally formed in theplastic member 226 is provided surrounding each of the annular flanges236 that are in communication with the channel 228. The plastic member226 of the housing portion 196 includes a pumping piston receivingaperture generally designated 240 and a pressure transducer receivingaperture generally designated 242. An annular flange 244 integrallyformed in the plastic member 226 in communication with the channel 228is provided surrounding the aperture 240, and an annular flange 246integrally formed in the plastic member 226 is provided surrounding theaperture 242. Semicircular channel portions generally designated 249 arealso provided around the annular flanges 244, 246. A recess 247 isprovided intermediate the flanges 244, 246 forming a continuation ofrecess 228. The ends of the flanges 236, 244, 246 are flush with thegenerally planar surface of the plastic member 226.

Referring now to FIG. 4C, the diaphragm 198 is preferably an injectionmolded length of silicone rubber that meets the appropriate U.S.Pharmacopia standards. The diaphragm 198 includes a longitudinallyextending reinforced seal portion 248 having a transverse width greaterthan the transverse width of the longitudinally extending fluid channel204 (FIG. 4A) that is received in the recess 228 (FIG. 4B). A pluralityof longitudinally spaced input fluid valve pads generally designated 250are provided on the longitudinally extending reinforced seal portion248. Individual ones of the valve pads 250 are aligned withcorresponding ones of the apertures 206 (FIG. 4A) and apertures 230(FIG. 4B). The valve pads 250 include an annular recess 252 that isindividually aligned with a corresponding one of the annular flanges 236(FIG. 2B) and an integral upstanding cyclindrical projection 254 thatare individually aligned with corresponding ones of the apertures 206(FIG. 4A) and apertures 238 (FIG. 4B).

A convex dome 256 surrounded by an annular recess generally designated258 is provided on the diaphragm 198. The recess 258 is aligned with theannular flange 244 (FIG. 4B) and the dome 256 is aligned with theaperture 240 (FIG. 4B) and the pumping chamber 208 (FIG. 4A). A thincircular portion 260 is provided on the diaphragm 198. The portion 260is aligned with the flange 246 (FIG. 4B) and with the pressure chamber218 (FIG. 4A). A vent valve pad generally designated 262 is provided onthe diaphragm 198 between the members 256, 260 in alignment with theapertures 216 (FIG. 4A), 234 (FIG. 4B), and a patient output valve padgenerally designated 263 is provided adjacent the cylindrical depression258 in alignment with the apertures 214 (FIG. 4A), 232 (FIG. 4B). Eachof the pads 262, 263 include an integral upstanding cylindricalprojection surrounded by an annular recess like those described abovefor the pads 250. The cylindrical projections of the valve pads 250,262, 263 have dimensions larger from the dimensions of the correspondingaligned apertures of the member 194 to provide a seal thereagainst toprevent fluid flow. The thickness of the portions 248, 256 (FIG. 4C) isselected to provide a stiffness sufficient to prevent their unintendedcollapse into the portions 204, 208 (FIG. 4A) during operation.

In the assembled condition of the disposable cassette as best seen inFIGS. 4D and 4E, the diaphragm 198 is sandwiched between the housingportion 194 and the housing portion 196. The longitudinally extendingseal portion 248 of the diaphragm 198 is received in the diaphragmreceiving recess 228, the solid cylindrical projections 254 of the valvepads 250, 262, 263 extend into corresponding ones of the apertures 230,232, 234, the dome portion 256 is received over the mouth of the pumpingchamber 208, and the cylindrical depression 254 is received over thedisc 218 and pressure chamber 212. Any suitable means such as ultrasonicwelding may be employed to secure the two housing portions together influid tight sealing engagement. The cassette is oriented in usepreferably at 45° to the vertical as described above in connection withthe description of FIG. 3A. As will readily be appreciated, any air inthe fluid flow channel 204 (FIG. 4A) rises upwardly therealong throughthe pumping chamber 208 (FIG. 4A) and fluid path 210 into the pressurechamber 212 (FIG. 4A). As appears below, the system controller isoperative to detect any air in the pressure chamber and to appropriatelyopen the vent output valve to vent the air and to alarm should thecondition persist. Since the air rises upwardly into the pressurechamber, the pumping chamber in normal operation is substantially freeof air. When the pumping chamber is controllably exhausted, only theintended infusate is administered into the patient output port therebypreventing the possibility of admitting air into the patient.

Individual ones of a plurality of valve plungers to be described arereceived in corresponding ones of the apertures 230, 232, 234 (FIG. 4B)that are reciprocally moveable to push corresponding upstandingcylindrical projections 254 (FIG. 4D) into sealing contact with theapertures 206, 214, 216 to control the state of actuation of thecorresponding fluid valves. The cyclindrical projections with theirassociated plunger withdrawn flex out of contact with the correspondingapertures to allow fluid flow into and out of the pumping chamber 208. Apumping piston to be described is received in the pumping pistonreceiving apreture 240 (FIG. 4B). The piston is reciprocally moveable tocontrollably push the dome 256 (FIG. 4C) into the pumping chamber 208 ascan best be seen in FIG. 4E. The fluid that accumulates therein duringeach pumping sequence to be described is thereby pumped through thepatient output port and into the circulatory system of a patient. Therate of reciprocating motion of the pumping piston, its travel distanceinto the chamber 208, and the time interval between pumping strokes isselected to controllably administer intended volumes of infusant inintended time intervals.

Referring now to FIG. 5, generally designated at 264 is a partiallyexploded perspective view with the cover removed of a valve and pumpingactuator of the infusion system having plural fluid input ports and atleast one patient output port according to the present invention. Theassembly 264 includes a plurality of fluid input port valve plungers 266each coaxially aligned with a corresponding one of the fluid inputapertures 230 (FIG. 4D), an output valve port plunger 268 coaxiallyaligned with the output port aperture 232 (FIG. 4B), a vent port plunger270 coaxially aligned with the collection bag aperture 234 (FIG. 4B),and a pumping chamber piston 272 coaxially aligned with the pumpingchamber aperture 240 (FIG. 4E).

Each of the fluid input valve plungers 266 are slideably mounted in andfastened to a corresponding one of a plurality of rocker arms 274 thatare individually pivotally mounted to a U-shaped support illustrateddashed at 276. A roller 278 is fastened to an end of each of the rockerarms 274. A cam 280 moving one lobe drives any selected one of therollers 278 to withdraw the corresponding fluid input plunger 266 out ofthe corresponding ones of the fluid input port apertures. A compressionspring 282 is slideably mounted on and fastened to corresponding ones ofthe plurality of fluid valve input plungers 266. The springs 282 actagainst one wall of the U-shaped support 276 urging the plungers 266into corresponding ones of the fluid input ports designated "A", "B","C", "D" of a cassette schematically illustrated at 283 to maintain thecorresponding valves in a normally closed condition.

The output valve plunger 268 is slideably mounted in and fastened to oneend a rocker arm 284 that is pivotally mounted to the support 276. Aroller 286 is fastened to an end of the rocker arm 284 remote from theend in which the plunger 268 is mounted. A cam 288, having two lobes180° apart, coaxial with the cam 280, drives the roller 286 to withdrawthe output valve plunger 268 out of the output valve aperture. Asolenoid 290 having a displacable ram 292 is fastened to the support 276with its ram 292 in contact with the end of the rocker arm 284 remotefrom the plunger 268. The ram 292 is selectably actuable to withdraw theoutput valve plunger 268 out of the output valve aperture. A spring 294is slideably mounted on and fastened to the plunger 268. The spring 294acts against the one wall of the U-shaped support 276 urging the plunger268 into the output port aperture for biasing the output valve in anormally closed condition. The cam 280 and the coaxial cam 288 aremounted for rotation with the shaft of a stepper motor 296. The systemcontroller controllably rotates the stepper motor 296 to selectivelyactuate the input and output valves to implement a desired pumpingsequence as appears more fully below. The lobes on the cams 280, 288 areso arranged as to prevent any input port and the output port from beingsimultaneously in an open condition for any rotary position of thestepper motor 296 to prevent unintended gravity flow infusion. Wheneverit is desired to simultaneously open any input port and the output portsuch as during priming, the system controller rotates the stepper motor296 to the position that opens the selected input port and actuates thesolenoid 290 to open the output port.

The vent plunger 270 is slideably mounted in and fastened to a rockerarm 298 that is pivotably mounted to the U-shaped support 276. Asolenoid 300 having a displaceable ram 302 is fastened to the supportwith its ram 302 in contact with the rocker arm 298. The ram 302 isselectably actuatable to withdraw the vent output valve plunger 270 outof the collection bag output aperture to open the vent valve. A spring304 is slideably mounted on and fastened to the vent plunger 270. Thespring 304 acts against one wall of the U-shaped support 276 urging theplunger 270 into the collection bag port to maintain the vent valve in anormally closed condition.

A pressure head 306 fastened to a pressure transducer 308 via alongitudinally adjustable mechanical linkage 310 is coaxially alignedwith the pressure chamber. The pressure head 306 includes an internalcoaxial rod, not shown, positioned over the aperture 220 (FIG. 4A) thatis displaced in a direction along its length in response to pressurevariations in the pressure chamber 212 (FIG. 4A). The pressuretransducer 308 converts the linear movement into an analog signalproportional to pressure in the pressure chamber.

A roller 312 is fastened to the end of the pumping piston 276 that isremote from the end that enters the pumping chamber 208 (FIG. 4A). A cam314 having a spiral shaped bearing surface mounted for rotation with theshaft of a stepper motor 316 selectively drives the roller 312 forcontrollably displacing the pumping piston 272 for reciprocating motioninto and out of the pumping chamber 208 (FIG. 4A). The support 276 ismounted in the housing for sliding motion by a mechanical linkagegenerally designated 303 connected between the lever 100 and the support276. The linkage 303 includes a rod 305 pivotally mounted on one end tothe lever 100 and connected on its other end to a member 307. A springbiased rod generally designated 309 is connected on one end to thesupport 276 and on its other end to a cam, not shown, interiorly of themember 307. A microswitch 311 is provided for sensing the axial positionof the lever 100. Lifting the lever 100 axially out of the safetymechanism 102 and rotating it either clockwise or counterclockwisedisplaces the member 307 thereby urging the rod 309 toward and away fromthe support 276 for moving the support 276 and therewith the plungersand pistons into and out of the associated apertures provided thereforon the cassette. The switch 311 senses the axial position of the lever100 to provide an indication of whether or not the cassette is locked inplace. Extending alignment rods 313 are provided that cooperate withassociated apertures provided therefor on the cassette, not shown, tohelp align the cassette in its intended operating position.

Referring now to FIG. 6, generally designated at 332 is a side view ofthe valve and pumping actuator illustrating position sensors of theinfusion system having plural fluid input ports and at least one patientoutput port according to the present invention. The position sensors areoperative to provide signal indications of the intended rotary positionof the stepper motors. An annular sleeve 324 is mounted for rotationwith the cams 280, 288 and stepper motor 296. As best seen in rolled outview in FIG. 7, the annular sleeve 324 has an open portion generallydesignated 328 and a closed portion generally designated 330. As shownin FIGS. 6 and 7, a dashed line 334 designates a first light path and adashed line 336 designated a second light path through which the sleeve324 rotates. The light paths 334, 336 may be provided by any suitablelight emitting and light receiving devices such as infrared emitters andcooperative infrared detectors. As the sleeve 324 rotates it alternatelytransmits and occludes the light paths 334, 336 providing signalindications to be described of the rotary position of the stepper motor296 to insure its intended rotary position.

An annular sleeve 338 is mounted for rotation with the cam 314 and thestepper motor 316. As best seen in rolled out view in FIG. 8, the sleeve338 has an open portion generally designated 342 and a closed portiongenerally designated 344. As shown in FIGS. 6 and 7, a dashed line 346designates a first light path and a dashed line 348 designates a secondlight path through which the sleeve 338 rotates. As the sleeve 338rotates it alternately occludes and transmits the light paths 346, 348providing signal indications to be described of the rotary position ofthe stepper motor 316 to insure its intended rotary position.

Referring now to FIG. 9, generally designated at 350 is a rolled outdiagram illustrating the operation of the valve and pumping actuator andposition sensors of the infusion system having plural fluid input portsand at least one patient output port according to the present invention.A line 352 illustrates the state of actuation of the "A" fluid inputport (FIG. 1), a line 354 illustrates the state of actuation of the "B"fluid input port (FIG. 1), a line 356 illustrates the state of actuationof the "C" fluid input port (FIG. 1), and a line 358 illustrates thestate of actuation of the "D" fluid input port (FIG. 1). The states ofactuation 352, 354, 356, 358 depend on the rotary position of thestepper motor 296 (FIG. 5) that drives the cam 280 (FIG. 5) into contactwith selected ones of the rollers 278 (FIG. 5) thereby displacing thecorresponding plungers 266 (FIG. 5) out of contact with thecorresponding cyclindrical valve projection 254 (FIG. 4D). A line 360illustrates the state of actuation of the patient output port 26 (FIG.1). The state of actuation of the output port depends on the rotaryposition of the stepper motor 296 (FIG. 5) that drives the cam 288 intocontact with the roller 286 (FIG. 5) thereby displacing the plunger 268out of contact with the cyclindrical valve projection 254 (FIG. 4D).When any one of the fluid input port valves are in an open condition asillustrated by the "peaked" portions of the lines 352, 354, 356, 358,fluid from the corresponding fluid container flows into the disposablecassette 94 (FIG. 3A) along the longitudinally extending fluid flowchannel 204 (FIG. 4A) and into the pumping chamber 208 (FIG. 4A) so longas the corresponding fluid input port is maintained in an open conditionand the pumping piston is withdrawn out of the pumping chamber. Afterfilling the pumping chamber with the selected fluid from any one of theplural fluid input ports, the system controller is operative to rotatethe cam 288 (FIG. 5) to either of the two "peaked" positions of the line360 (FIG. 9) to open the output valve 26 (FIG. 1) to allow fluid to flowthrough the patient line 120 (FIG. 3A). The system controller during apumping sequence is operative to take several pressure measurements andto alarm when appropriate in a manner to be described. Fluid admittedinto the cassette from the "B" and from the "C" fluid input ports areadministered from the left hand "peaked" position of the line 360, andfluid admitted into the cassette from either the "A" and from the "D"fluid input ports are administered from the right hand "peaked" positionof the line 360. In priming mode for the patient output line, the systemcontroller is operative to rotate the stepper motor 296 to the positionthat opens the selected one of the fluid input ports, and to activatethe solenoid 290 (FIG. 5) to open the patient output valve to allowpriming fluid to flow from the selected fluid input port through thecassette and into the patient output line to prevent the possibility ofadmitting air into the patient. The sleeve 326 (FIG. 6) alternatelyoccludes and transmits light along the light paths 334, 336 (FIG. 6)producing signal indications designated 362 and 364 of the rotaryposition of the stepper motor 296 (FIG. 6) to within one step accuracyof the left and right hand "peaked" positions of the line 360. Asappears below, the signals 362 and 364 are used by the system controllerto insure the proper orientation of the cam 280 (FIG. 5). A line 366illustrates a pumping sequence of the pumping plunger 272 (FIG. 5),beginning at a vertical line designated 367 and ending at a verticalline designated 369. The sleeve 338 (FIG. 6) alternately occludes andtransmits light along the light paths 346, 348 (FIG. 6) producing signalindications 368, 370 of the position of the stepper motor 316 (FIG. 6)to within one step accuracy of the start and end positions of the piston242 (FIG. 5) during a pumping sequence. As appears below, the signals368, 370 are used by the system controller to insure proper orientationof the cam 314 (FIG. 5).

Referring now to FIG. 10, generally designated at 372 is a schematicdiagram illustrating a preferred embodiment of the system controller ofthe infusion system having plural fluid input ports and at least onepatient output port according to the present invention. The systemcontroller 372 includes a first processor 374 and a second processor 376slaved to the first processor 374. A bit serial asynchronouscommunication link 378 interconnects the processors 374, 376. Theprocessor 374 controls operator input and output (I/O), and down loadsinstructions over the serial communication link 378 into dual ping-pongbuffers 379 for execution by the processor 376. The processor 376controls in accordance with the instructions the state of actuation ofthe fluid input port valves and of the patient and vent output valves,controls the reciprocating motion of the pumping chamber piston at arate and for a duration specified by the instructions, reads informationrepresentative of the pressure in the pressure chamber and writesinformation to the processor 374 representative of alarm situations andpressure data. As appears more fully below, the processor 374 isoperative in response to the measured pressure data to adjust thereciprocating motion of the pumping piston to adapt desired to actualfluid flow rates.

The system I/O and pump control processor 374 includes a data bus 380and an address bus 382 connected thereto in the usual manner. Aplurality of function and data keys 384 described above in connectionwith the description of FIG. 3B are connected by an interface 386 to thedata bus 380. An operator interactive display 388 described above inconnection with the description of FIG. 3B and an associatedelectrically erasable E2 ROM 390 are connected to the data bus 380 by aninterface 392. A real time clock 394, a plurality of infusion LED's 396,and a nurse call signal generator 398 are connected by an interface 400to the data bus 380. A data RAM 402 is connected to the data bus 380 andto the address bus 382. A program PROM 404 is connected to the addressbus 382 and to the data bus 380. An auxiliary pump processor 406 isconnected to the data bus 380 via an interface 408 and a secondauxiliary pump 410 is connected to the data bus 380 via an interface412. A RS 232 interface 414 is connected to the data bus 380 via aninterface 416. A peripheral device 418 such as a display terminal or acentral control computer interface is connected to the RS 232 interface414. The interfaces 386, 392, 400, 408, 412, and 416 format and bufferdata between the data bus and the associated devices in a manner wellknown to those skilled in the art. An address decoder 420 is connectedto the address bus and to the interfaces 382, 392, 400, 408, 412, and416 via a plurality of control lines 422. The address decoder 420decodes the addresses appearing on the address bus and activates thecorresponding control line to enable the addressed peripheral device fordata reads and writes via the data bus 380. Battery and alarm LED's 424described above in connection with the description of FIG. 3B areoperatively connected to the processor 374.

Referring now to FIG. 11, generally designated at 426 is a data file ofthe RAM 402 (FIG. 10). The data file 426 includes a block of selectivelyaddressable RAM memory generally designated 428 for fluid input port"A", a block of RAM memory generally designated 430 for fluid input port"B", a block of RAM memory generally designated 432 for fluid input port"C", and a block of RAM memory generally designated 434 for fluid inputport "D". Each block of RAM memory 426, 428, 430, and 432 atcorresponding preselected address locations thereof specify an operatorselected data structure for the corresponding fluid input port. Thesystem I/O and pump control processor 374 selectively addresses the RAM402 (FIG. 10) over the address bus 382, and writes into the selectivelyaddressed RAM location the data selected by the operator over the databus 380 as described above in connection with the description of FIG.3B. The data structure for each line includes data representative ofwhether it is a primary or piggyback line. The data structure forprimary lines includes data representative of infusion rate, infusionvolume, infusion duration, and fluid container volume. The datastructure for piggyback lines includes data representative of diluteline, dilute volume, and dilute rate for piggyback dilutions, and datarepresentative of duration (Q) and repeat interval (X) for timesequential piggyback lines. The data structure for each line includesdata representative of "prime" mode, "override" mode, and "normal-on"mode, and data representative of start time either after a selecteddelay or after infusion on a designated line. The data structure foreach line includes data representative of syringe, and the preselectedline for unsticking the syringe plunger. The data structure for eachline includes data representative of flush and the selected flush line,flush volume, and flush rate. The data structure for each line furtherincludes data representative of "call back", and data representative ofmeasured pressure including patient pressure, compliance pressure, andbottlehead pressure to be described.

The data file 426 includes a block of selectably addressable RAM memorygenerally designated 436. The data structure of the block of RAM 436 foreach line specifies data representative of the current history of theinfusions already pumped on that line.

The data file 426 includes a block of selectively addressable RAM memorygenerally designated 438 that specify global parameters for all thelines. The data structure of the block of RAM 438 specifies datarepresentative of current time, maximum occlusion pressure, maximuminfusion rate and volume, and KVO rate.

Returning now to FIG. 10, the PROM 404 includes in preselected addresslocations thereof the code specifying the program for the system I/O andpump control processor 374. The PROM 404 also includes at preselectedaddress locations thereof the display templates that prompt the systemoperator for both selecting a desired course of infusion and forselecting and controlling system operation described above in connectionwith the description of FIG. 3B.

A data bus 426 is operatively connected to the pump control processor376. RAM and PROM for the pump processor, not shown, are associatedtherewith in the usual manner. The pump control processor PROM containsthe code specifying any one of possible pumping sequences to bedescribed. Conventional latched drives 428 operatively connected to thedata bus 426 are connected to a valve stepper motor 430. Conventionallatched drives 432 operatively connected to the data bus 426 areconnected to a pump stepper motor 434. An analog to digital converter(ADC) 436 operatively connected to the data bus 426 is connected to apressure transducer 438 via a conventional analog signal conditioningmodule 440. Voltage inputs designated "V₁ -V₆ " are connected to the ADC436 to monitor system power level as described above in connection withthe description of FIG. 1. A plurality of control lines 442 areoperatively connected to the pump control processor 376 for selectingthe latched drives 428, for selecting the latched drives 432, and forselecting the analog to digital converter 436. A patient line solenoid439 is connected to the latched drives 428, and a vent valve solenoid441 is connected to the latched drives 432. Position sensors generallydesignated 444 operatively connected to the pump control processor 376and the latched drives 428, 432 provide signal indicationsrepresentative of the rotary position of the valve stepper motor 430 andof the rotary position of the pump stepper motor 434 described above inconnection with the description of FIGS. 6-9. The pump control processoris operative in the usual manner to enable selected ones of the devices428, 432, and 436 by the corresponding control line, and to read andwrite at the appropriate times during a pumping sequence data theretoover the data bus 426.

Referring now to FIG. 12, generally designated at 448 is a tableillustrating an instruction byte produced by the system I/O and pumpcontrol processor 374 (FIG. 10) for controlling the pump controlprocessor 376 (FIG. 10). The instruction byte includes eight bitsdesignated 0 through 7. The one bit designated "ALL" of the bit fieldspecifies that all data read by the pump processor is to be read by tothe system I/O and pump control processor. The two bit designated "V₁-V₆ " of the bit field specifies that the battery and regulator voltagedata measured by the analog to digital converter is to be read by thesystem I/O and pump control processor. The three bit of the bit fielddesignated "D₀ -D₇ and C₄ " specifies either that the maximum occlusionpressure are to be written by the system I/O and pump processor to thepump processor or that the pressure and error data bytes "D₀ -D₇ " to bedescribed are to be read by the system I/O and pump control processorfrom the pump processor. The four bit designated "norm and other" of thebit field specifies whether the system is to operate in the normal modeor not. The five bit designated "read/write" of the bit field specifieswhether data is to be read by the pump control processor or whether datais to be written by the pump control processor. The six bit designated"X/Y" of the bit field specifies which of the ping-pong buffers is to bereceive the next command. The seven bit designated "abort" of the bitfield specifies whether an abort is to be effected by the pump controlprocessor. As shown by the table 448, the first instruction specifieswhether the X or the Y buffer is to be aborted. The second instructionreads a status byte designated "S" to be described. The thirdinstruction reads D₀ through D₇. The fourth instruction reads V₀ to V₆.The fifth instruction reads S, D₀ through D₇, V₀ through V₆, and C₀through C₄ to be described. The sixth instruction writes C₀ through C₃and reads D₀ through D₂. The seventh instruction writes C₄, and readsD₃. The eighth instruction instructs the pump processor to take areference pressure measurement designated 0 PSI to be described.

Referring now to FIG. 13A, generally designated at 450 is a status byte"S". The status byte is produced by the pump control processor andincludes data representative of the state of the X, Y ping-pong buffersand of the mode of operation of the pump control processor. The statusbyte 450 includes eight bit positions 0 through 7, with the zero and onebits of the bit field specifying control mode, the second bit of the bitfield specifying Y error buffer, the third and fourth bits of the bitfield specifying the state of Y buffer, the fifth bit of the bit fieldspecifying an X buffer error, and the sixth and seventh bits of the bitfield specifying the state of the X buffer. As shown in the state table,a "0, 1" specifies that the corresponding X or Y buffer is waiting toexecute; a "1, 0" specifies that the corresponding instruction is beingexecuted; a "1, 1" specifies that the corresponding buffer is ready fora new instruction; and a "0, 0" specifies an initialization state forthe corresponding buffer. As shown in the control table designated"CNTL", a "0, 0" specifies continuing the current control function and a"1, 1" specifies stopping the current funtion.

Referring now to FIG. 13B, generally designated at 452 is a timingdiagram illustrating the communications protocol of the processors 374,376 (FIG. 10). The boxes above the dashed line 454 illustrate theinstructions written from the system I/O and pump control processor 374to the pump control processor 376, and the boxes below the dashed line454 illustrate the data read from the pump control processor by thesystem I/O and pump control processor 374. For the exemplarycommunications protocol, the pump control processor 374 sends over thetransmission link 378 an instruction designated "I RD STAT" to read thestatus byte as illustrated at 456. The pump control processor 376receives the instruction as illustrated at 458, and sends the statusbyte having the control bits "0, 0" back to the system I/O and pumpcontrol processor 374 as illustrated at 460. The system I/O and pumpcontrol processor receives the status byte as illustrated at 462, andsends it back to the pump control processor instructing it to continueas illustrated at 464. The process continues until the system I/O andpump control processor 374 instructs the pump control processor 376 tostop as illustrated by the box 466 having the control bits "1, 1". Thepump control processor continues until it receives the instruction tostop as illustrated at 468 and sends it back to the system I/O and pumpcontroller processor as illustrated by the box 470. The system I/O andpump control processor then sends an acknowledge instruction designated"ACK" to the pump control processor as illustrated by the box 472, whichis received by the pump control processor 376 as illustrated by the box474. It will be appreciated that a similar communications protocol isimplemented for each of the instructions and commands written by thesystem I/O and pump control processor to the pump control processor.

Referring now to FIG. 14, generally designated at 476 is the C₀ commandbyte; generally designated at 478 is the C₁ command byte, generallydesignated at 480 is the C₂ command byte, generally designated at 482 isthe C₃ command byte, and generally designated at 484 is the C₄ commandbyte. The 0 through 6 bits of the bit field of the C₀ byte 476 specify anumber of microstrokes per pump stroke, and the seventh bit of the bitfield specifies priming. The 0 through 12 bits of the bit field of theC₁, C₂ bytes 478, 480 specify the time per pump stroke, preferably intenths of a second, and the 13 through 15 bits of the bit field of theC₁ byte 478 designated "T₀ -T₂ " specify which of the pump processorPROM pumping sequences to be described is to be executed. The 0 through4 bits of the bit field of the C₃ byte 482 specify the number of pumpstrokes, the fifth and sixth bits of the bit field of the C₃ byte 482specify from which fluid input port fluid is to be administered, and theseventh bit of the bit field specifies either that the vent output valveor the patient line output valve are to be actuated. The C₄ byte 484specifies the maximum occlusion pressure selected by the systemoperator.

Referring now to FIG. 15, generally designated at 488 is the D₀ databyte. The D₀ data byte represents the bottle height pressure designated"P2" read by the pump processor and written in pump processor RAM duringthe pumping sequence. The bottle height pressure is the ADC reading ofthe pressure chamber when only an input valve is open normalized by the0 PSI value. The D₁ data byte is generally designated at 490. The D₁data byte represents the air-in-line compliance pressure designated "P4"read by the pump processor and written in pump processor RAM during thepumping sequence. The air-in-line compliance pressure as appears belowis the difference of the ADC reading of the pressure chamber when thepiston is successively driven partially in the pumping chamber and allvalves are closed. The D₂ byte is generally designated at 492. The D₂data byte represents volume correction designated "N1" and "N2" to bedescribed read by the pump processor and written in pump processor RAMduring the pumping sequence. The volume correction data as appears belowdepends on the pressure data and is employed to adapt actual to desiredpumping rates. The D₃ data byte is generally designated at 494. The D₃data byte represents the zero PSI pressure designated "P1" read by thepump processor and written in pump processor RAM during the pumpingsequence. The 0 PSI pressure is the ADC reading of the pressure chamberwhen any input is just opened and the output valve is closed and thepumping piston is withdrawn prior to water hammer effects. The D₄ databyte is generally designated at 496. The D₄ data byte representsmatching pressure designated "P3" to be described read by the pumpprocessor and written in pump processor RAM during the pumping sequence.The D₅ data byte is generally designated at 498. The D₅ data byterepresents the patient pressure designated "P5" read by the pumpprocessor and written in pump processor RAM during the pumping sequence.The D₆ and D₇ bytes generally designated 500 and 502 have data thereinrepresentative of various error and alarm conditions that the pumpcontroller monitors. The D₆ and D₇ data bytes are written during apumping sequence in pump processor RAM. The D₆ and D₇ data bytes includedata representing whether the stepper motors out are of proper rotaryposition, patient pressure greater than maximum occlusion pressure,air-in-line pressure less than minimum compliance pressure, empty bottlepressure, and cassette locking lever out of place.

Referring now to FIG. 16, generally designated at 504 is a data flowchart illustrating the operation of the infusion system having pluralfluid input ports and at least one patient output port according to thepresent invention. As illustrated by the blocks 505, 506, the system I/Oand pump control processor is operative to determine that a valid key,or combination of keys, has been entered. If a valid key or keycombination has been entered, the processor is operative as shown by ablock 508 to select the corresponding display template stored in PROM asshown by blocks 508, 510 and to display the selected template on theoperator interactive display as shown by a block 512. If the displaytemplate corresponds to either the pump command display templates or therate/vol./time display templates, the processor is operative to addressfor each data field the corresponding data locations in the data file514 as illustrated by a block 516, and to write the operator selecteddata into the corresponding address locations of the data file for anyselected one or more of the plural fluid input ports A, B, C, and D. Asillustrated by a block 517, the system I/O and pump control processor isoperative to write the data into the RAM data file to provide RAMredundancy for preventing errors. The 0 through 6 bits of the bit fieldof the C₀ command (FIG. 14) and the 13 through 15 bits of the bit fieldof the C₁ command (FIG. 14) are specified by the data file.

As shown by a block 518 the system I/O and pump control processor isoperative to read the data file address locations and the time as shownby a block 521 to determine if it should institute a pumping sequence onan active line. As shown in FIG. 17, which generally designates at 523 aflow chart of the active line sequencer, the processor is operative todetermine whether the data file specifies operation in the priming modeas shown by a block 520. If the data file contains data representativeof priming for any one of the input valves, the processor is operativeto produce instructions to stop all other pump functions as shown by theblock 522, to produce instructions to prime the designated line as shownby a block 524, to produce instructions to inactivate all the fluidlines as shown by a block 526, and to return processing to the block519. If the data file specifies operation in the override mode as shownby a block 528, the processor is operative to produce instructions tostop all nonoverride functions as shown by a block 530, to produceinstructions to pump the line designated at the specified rate as shownby a block 532, to inactive all fluid lines as shown by a block 534, andto return processing to the block 519. If the data file specifiesoperation in the flush mode as shown by a block 536, the processor isoperative to produce instructions to suspend all nonflush functions asshown by a block 538, to produce instructions to flush the designatedline as shown by a line 540, to reset the flush line as shown by a block542, and to return processing to the block 519 as shown by a block 544.If the data file specifies operation in the auto-on mode as shown by ablock 546, the processor is operative to determine whether the time forinfusion is the present time or whether more delay is needed as shown bya block 548. If no more time is needed, the processor is operative todetermine whether the data file designates the line as a primary line asshown by a block 550. If the line is a primary line, the processor isoperative to determine whether the data file specifies call back asshown by a block 552. If call back is specified, the processor isoperative to sound an alarm and to pump in the KVO mode as shown by ablock 554. If no call back is specified in the data file, the processoris operative to produce instructions to pump the specified line as shownby a block 556, and returns processing to the block 519 as shown by ablock 558. If the line is a piggyback line, the processor is operativeas shown by a block 551 to determine whether call back is specified inthe data file. If call back is specified in the data file, the processoris operative to sound an alarm and to pump in the KVO mode as shown by ablock 553. If no call back is specified, the processor is operative todetermine if the data file specifies a syringe as shown by a block 555.If a syringe is specified, the processor is operative to produceinstructions to stop all other functions and to unstick the syringeplunger as shown by a block 557. The processor is then operative toproduce instructions to pump from the syringe at the selected rate asshown by a block 559, and to return processing to the block 519 as shownby a block 561. If syringe is not specified, the processor is operativeto produce instructions to pump the designated line at the specifiedrate as shown by the block 556, and returns processing to the block 519as shown by the block 558. The active line sequencer specifies the 7 bitof the bit field of the C₀ command and the 5, 6, and 7 bits of the bitfield of the C₃ command.

Returning now to FIG. 16, if any of the lines are active as describedabove in connection with the description of FIG. 17, the processor isoperative to calculate the number of strokes for the pumping plunger toeffectuate the desired duration and rate of infusion. The processor ispreferably operative to calculate the number of strokes per secondaccording to the following relation: ##EQU1## where Rate_(I) is thespecified infusion rate in milliliters per hour and VOL_(eff) is theeffective infused volume calculated as described below. The tenths ofsecond per stroke data is written in the 0 through 12 bits of the bitfield of the C₁ and C₂ commands bytes.

The processor is operative to buffer the instructions and commandsdescribed above in connection with the description of FIGS. 12 and 14 ina command queue as shown by a block 566, which are written to the pumpcontrol processor as shown by a block 568 into a specified one of the Xor Y buffers as illustrated by the blocks 570, 572. As illustrated by ablock 574, the pump control processor is operative to fetch theinstructions from the appropriate buffer, and executes the specifiedpump control sequence as shown by a block 576 to controllably rotate thevalve stepper motor to close and open the designated fluid input portsas illustrated by a block 578 and to controllably rotate the pistonstepper motor to repetitively actuate the pumping piston as illustratedby a block 580. The pump control processor is operative during thepumping sequence to store in RAM the LED sensor signals from the valvestepper motor sleeve as illustrated by a block 582, and to store in RAMthe LED sensor signals from the pump stepper motor sleeve as illustratedby a block 584. The pump processor is operative to read the analog todigital converter as shown by a block 586, to activate the vent outputvalve solenoid and the patient output line solenoid as shown by a block589, and to write into pump control processor RAM the D₀ -D₇ data asshown by a block 591 during the pumping sequence.

Referring now to FIG. 18, generally designated at 592 is a flow chartillustrating an exemplary pumping sequence of the pump controlprocessor. The sequence 592 is preferably employed to controllably pumpinfusate at comparatively low operator selected rates of flow. As shownby a block 594, the processor is operative to open the specified one ofthe fluid input port valves, to withdraw the pumping piston, and towrite the A/D reading into the D₃ RAM data location to measure 0 PSI.The processor is then operative to wait a predetermined time to allowfluid to flow from the selected input port into the pumping chamber asshown by a block 596.

The processor is then operative to write the A/D reading normalized bythe 0 PSI reading into the D₀ data RAM location to measure thebottlehead pressure of the corresponding fluid container designated P2.The processor is then operative to close the valves as shown by a block600 and to drive the pumping piston a selected distance, preferably foursteps of the stepper motor, into the pumping chamber, and delays asshown by a block 602. The processor is then operative to write the A/Dreading of the pressure transducer in RAM to take the matching pressuredesignated P3 as shown by a block 604. The processor is then operativeto drive the pumping piston into the pumping chamber a further selecteddistance, preferably eight additional steps of the stepper motor, anddelays as shown by a block 606. The processor is then operative to writethe A/D reading of the pressure transducer designated P4 into RAM asshown by a block 608.

As shown by a block 610, the processor is then operative to compare thedifference of the readings to determine whether air is in the line, towrite the difference in the readings into the D₁ RAM data location, andto either proceed or alarm in dependence on whether the change inpressure is below a minimum preselected reference compliance pressure.As shown by a block 612, if air is in the line, the processor isoperative to abort the pumping sequence. The processor is then operativeto vent air from the line using a pumping sequence to be described, toalarm as shown by a block 614 if air is in the line preferably for threeconsecutive measurements, and processing for each measurement isreturned to the block 594. As shown by a block 616, if no air is in theline, the processor is operative to withdraw the pumping piston out ofthe pumping chamber a preselected distance selected according to themeasured pressures preferably calculated according to the relation8(P4-P5L)/(P4-P3) steps of the stepper motor. The pressure P5L is the P5pressure from the last stroke to be described. If P5L has yet to bemeasured in the pumping sequence, the processor assumes a specifiedvalue for the pressure P5L preferably equal to 0 PSI+5. The processor isthen operative to open the patient output line valve as shown by a block618 and to write the A/D reading of the pressure transducer into RAM tomeasure the patient pressure designated P5 as shown by a block 620.

As shown by a block 622, the processor is then operative to determinewhether the pressure P5 is less than the pressure P3. As shown by ablock 624, if the pressure P5 is greater than the pressure P3, theprocessor is operative to successively drive the pumping piston step bystep fully into the pumping chamber and to write the corresponding A/Dreading into RAM. The processor is operative to compare the pressurereading for each step to the maximum occlusion value specified in the C4command byte 484 (FIG. 14) to determine whether the patient line isoccluded. If the line is occluded, the processor is operative to alarmif the pressure doesn't drop within a predetermined time interval, forexample, 30 seconds. The processor is then operative to close the inputand output valves as shown by a block 626. As shown by a block 628, theprocessor is then operative to withdraw the pumping piston and write A/Dreading into RAM. The processor then steps the pumping piston into thepumping chamber incrementally by steps of the stepper motor and writesthe A/D reading into RAM. The processor is operative to repeat thisprocess until the measured pressure equals the matching pressure P₃ andstores that rotary position of the pumping piston stepper motordesignated N₂ in RAM where the measured pressure equals the pressure P₃.As shown by a block 630, the processor is then operative to drive thepumping piston fully into the pumping chamber and to open the patientoutput line valve as shown by a block 632.

If the pressure P5 is less than the pressure P3, the processor isoperative to successively drive the pumping piston almost fully into thepumping chamber, and to write the corresponding A/D reading into RAM.The processor is operative to compare the pressure reading for each stepto the maximum occlusion value specified in the C4 command byte 484(FIG. 14) to determine whether the patient line is occluded. If the lineis occluded, the processor is operative to alarm if the pressure doesn'tdrop within a predetermined time interval, for example, 30 seconds. Theprocessor is then operative to close the input and output valve as shownby a block 636. As shown by a block 638, the processor is then operativeto incrementally drive the pumping piston step by step into the pumpingchamber and to write the corresponding A/D reading in RAM. The processorcontinues the process until the measured pressure is equal to thematching pressure P3 and stores the rotary position of the stepper motorat which the measured pressure equals the pressure P3 designated N₁ inRAM. As shown by a block 640, the processor is then operative to returnthe piston to the position of the stepper motor in the block 634, and toopen the patient output line as shown by a block 642. The processor isthen operative to drive the piston fully into the pumping chamber topump the corresponding fluid into the patient output line as shown by ablock 644.

Referring now to FIG. 19, generally designated at 646 is a flow chartillustrating another exemplary pumping sequence of the pump controlprocessor. The sequence 646 is preferably employed to pump infusate at acomparatively higher operator selected rates of flow. The flow chart 646is similar to the flow chart 592 (FIG. 18) except that the processor isoperative to skip some of the patient pressure monitoring steps of theflow chart of FIG. 18 to allow for faster pumping rates. As describedabove, the particular pumping sequence is specified by the state of the13, 14, and 15 bits of the bit field of the C₁ command byte, and thatthe processor can be instructed to do several cycles of the pumpingsequence illustrated in FIG. 19 followed by a sequence of the pumpingsequence illustrated in FIG. 18 repetitively. As shown by a block 648,the processor is operative to open a selected fluid input port valve, towithdraw the pumping piston, and to write the A/D reading of thepressure transducer into the D₃ data byte. The processor is thenoperative to wait to allow the pumping chamber to fill with fluid fromthe selected fluid input port as shown by a block 650. The processor isthen operative to write the A/D reading of the pressure transducer intothe D₀ data byte as shown by a block 652. As shown by a block 654, theprocessor is then operative to close the fluid input and output portvalves and then to drive the pumping piston a preselected distance intothe pumping chamber, preferably twelve steps, and to delay as shown by ablock 656. The processor is then operative to write the A/D reading ofthe pressure transducer into RAM to measure the compliance pressure fordetermining air in line as shown by a block 658.

As shown by a block 660, the processor is then operative to determinewhether the compliance pressure minus the 0 PSI pressure is greater thanthe preselected maximum compliance pressure to determine whether thereis air in line. As shown by a block 662, if there is air in line, theprocessor is operative to abort the current pumping sequence, to ventair from the line, to alarm as shown by a block 646 if air remains inthe line preferably for three consecutive measurements, and processingfor each measurement is returned to the block 648. As shown by a block666, if no air is in the line, the process is operative to open thepatient output line. The processor is then operative to drive thepumping piston into the pumping chamber and write the A/D reading intoRAM. If the pressure is greater than the maximum occlusion pressure, theprocessor is operative to alarm as shown by a block 668.

Referring now to FIG. 20, generally designated at 670 is another pumpingsequence of the pump control processor. The sequence 670 is preferablyemployed to vent air from the fluid flow path as described above inconnection with the description of FIGS. 18 and 19. As shown by a block672, the processor is operative to open the preselected fluid input portto be used for venting. The processor is then operative to withdraw thepumping piston out of the pumping chamber to allow the fluid to fillinto the pumping chamber as shown by a block 674. The processor is thenoperative to open the vent valve as shown by a block 676 and to drivethe pumping piston into the pumping chamber to clear air from the fluidpath as shown by a block 678. As shown by a block 680, the processor isthen operative to close the vent valve. It will be appreciated that airmay also be removed from the fluid flow path by the pressure of thegravity head without driving the piston into the pumping chamber.

Referring now to FIG. 21, generally designated at 684 is a flow chartillustrating another exemplary pumping sequence of the pump controlprocessor. The sequence 684 is preferably employed to unstick theplunger of a syringe fluid input. As shown by a block 686, the processoris operative to open the valve of the fluid port preselected as theunsticking fluid port and to withdraw the pumping piston to allow theunsticking fluid to flow into the pumping chamber as shown by a block688. The processor is then operative to close the unsticking fluid valveas shown by a block 690 and to open the fluid input having the syringeas shown by a block 692. The processor is then operative to drive thepumping piston into the pumping chamber as shown by a block 694. Theexpelled fluid is thereby pumped through the cassette and into thesyringe to unstick the plunger. The processor is then operative to closethe syringe valve as shown by a block 696 and then to open theunsticking fluid valve as shown by a block 698. The processor is thenoperative to withdraw the pumping piston out of the pumping chamber toallow the unsticking fluid to flow into the pumping chamber as shown bya block 700. The processor is then operative to close the unstickingfluid valve as shown by a block 702 and to open the syringe valve asshown by a block 704. The processor is then operative to drive thepumping piston into the pumping chamber to once again displace fluidtherefrom into the syringe to unstick its plunger as shown by a block706. The processor is then operative to do two cycles from the syringeto remove the fluid pumped thereinto to unstick the syringe plunger asshown by a block 708.

Referring now to FIG. 22, generally shown at 710 is another exemplarypumping sequence of the pump control processor. The sequence 710 ispreferably employed to abort a pumping sequence as described above in aconnection with the description of FIGS. 18 and 19. As shown by a block712, the processor is operative to close the fluid input and patientline output port valves and to open the vent valve as shown by a block714. The processor then operative to drive the piston into the pumpingchamber as shown by a block 716. The processor is then operative toclose the vent valve as shown by a block 718 and to open the patientoutput line valve as shown by a block 720.

Returning now to FIG. 16, as shown by a block 722, the system I/O andpump control processor is then operative to read the status and datainformation compiled by the pump processor during the pumping sequencesdescribed above and write it back to the data file. The processor isthen operative to strip off the D₀ through D₅ data bytes as shown by ablock 724. As shown by a block 726, the processor is operative to adaptthe desired volume to the actual volume preferably according to thefollowing relations,

    VOL.sub.eff =V.sub.0 -A(100-N2)                            1.

    VOL.sub.eff =V.sub.0 -A(88-N1)                             2.

where V₀ is the volume of the pumping chamber, A is the volume displacedfrom the pumping chamber per step, 100 represents the total number ofsteps of the stepper motor of a pumping sequence, 88 refers the rotaryposition where the pumping piston is driven almost completely into thepumping chamber as described above in connection with block 634 (FIG.18), and N1 and N2 are determined as described above in connection withblocks 628, 638 (FIG. 18).

As shown by a block 728, the processor is operative if the statusinformation written into the data file indicates any of the severalerror and alarm conditions to select the corresponding display templateas shown by a block 730, to display it on the operator display as shownby a block 732, and to generate the appropriate audible and visualalarms as shown by a block 734. As shown by a block 736, if any of theexplain, history, mute or status keys are depressed, the processor isoperative to select the appropriate display template as shown by a block730 and to display it on the operator interactive display as shown bythe block 732.

Referring now to FIG. 23, generally designated at 626 is a diagramillustrating an exemplary operating sequence of the infusion systemhaving plural fluid input ports and at least one patient output portaccording to the present invention. The sequencing diagram 626illustrates pumping from the "B" fluid input port, and then pumping fromthe "D" fluid input port, utilizing the pumping sequence of FIG. 19,although it will be appreciated that any other valve order and pumpingsequence is a variation of that specifically illustrated in FIG. 23. Aline 738 illustrates the state of actuation of the "A" input valve, aline 740 illustrates the state of actuation of the "B" fluid input port,a line 742 illustrates the state of actuation of the "C" fluid inputvalve, and a line 744 illustrates the state of actuation of the "D"fluid input port value. A line 746 illustrates the state of actuation ofthe output valve designated "O" and a line 748 illustrates the rotaryposition of the pump plunger stepper motor during the exemplarysequence. A line 750 illustrates the reading of the pressure transducer.

The pump processor is operative to rotate the valve stepper motorthrough the open position 752 of the "A" port and stops at the openposition 754 of the "B" port. With the "B" valve in the open conditionas the pumping piston is withdrawn as illustrated at 756, fluid flowsfrom the "B" fluid input port into the cassette and through thelongitudinally extending fluid passageway thereof into the pumpingchamber. The processor is operative to take the A/D reading of thepressure transducer to measure the 0 PSI value as shown at 758. Aftersufficient delay to allow filling of the pumping chamber, the processoris operative to take a reading from the analog to digital converter asshown at 760 to measure the bottle height pressure. The processor isthen operative to close the "B" fluid input port as shown at 762. Thepump processor is then operative to controllably push the pumping pistoninto the pumping chamber by rotating the pump stepper motor preferably12 steps as illustrated at 764. The pump processor is then operative totake the reading of the analog to digital converter with the pumpingplunger partially into the pumping chamber to measure the correspondingpressure as illustrated at 766. The change in pressure 768 is indicativeof air-in-line and is stored in the appropriate data byte. Assuming forthe exemplary sequence that no air is in line, the processor is thenoperative to rotate the valve stepper motor to open the output valve asillustrated at 770 and to rotate the pump stepper motor to controllablydisplace the piston into the pumping chamber as illustrated at 772. Theprocessor is operative to take the A/D reading during pumping and toalarm if there is an occlusion situation, not illustrated. The processoris then operative to rotate the valve stepper motor to close the outputvalve as shown at 774, and to repeat the cycle until the desired volumeof fluid is administered into the patient through the "B" input port. Atthe appropriate time, the processor is then operative to rotate thevalve stepper motor through the open position of the "C" port as shownat 776 to the open position 778 of the "D" port to commence a pumpingsequence through the "D" fluid input port. The above cycle is thenrepeated for the "D" port but is omitted for brevity of explication.

It will be appreciated that many modifications of the presentlydisclosed invention will be apparent to those skilled in the art withoutdeparting from the scope of the appended claims.

What is claimed is:
 1. An infusion system having plural fluid inputports and a fluid output port, comprising:a fluid manifold having:afluid flow channel, plural fluid input valves each connected to acorresponding one of said plural fluid input ports, a patient outputvalve connected to said fluid output port and in fluid communicationwith said plurality of fluid input valves via said fluid flow channel,means, in fluid communication via said fluid flow channel with saidplurality of fluid input valves and said fluid output valve, for pumpingfluid from any input port through said output port, and a pressurechamber in fluid communication with said plural fluid input valves anddisposed intermediate and in fluid communication with said pumping meansand said fluid output valve via said fluid flow channel, said pressurechamber interposed within and formed discretely from said fluid flowchannel; a system controller having memory; means coupled to said systemcontroller for writing into said memory first data representative of adesired course of infusion including at least one of time sequence offluid to be administered from any one or more of said fluid input ports,rate of fluid to be administered from corresponding ones of said any oneor more of said fluid input ports, and a duration of fluid to beadministered from corresponding ones of said any one or more of saidfluid input ports; a pressure transducer operatively connected to saidpressure chamber and coupled to said system controller for providingsecond data representative of the pressure in said fluid manifold at anyof said input valves, said pumping means, and said output valve; andmeans coupled to said system controller and to said fluid manifold andoperative in response to said first and second data for selectivelyactuating individual ones of said fluid input valves in dependence onsaid first data to admit a selected fluid into said fluid manifold andfor both selectively actuating said output valve, and said pumping meansin dependence on said first and second data.
 2. The invention of claim1, wherein said manifold further includes a vent output port and anassociated valve that is in fluid communication with said plural fluidinput valves.
 3. The invention of claim 2, wherein said systemcontroller is selectively operable to control administration of fluidfrom any selected one of said plural fluid input ports through saidmanifold and out said vent port to flush the manifold of any air thereinto prevent air embolism.
 4. The invention of claim 3, wherein saidsystem controller is operative to control pumping of fluid from anyselected one of said plural fluid input ports through said manifold andout said vent port.
 5. The invention of claim 3, wherein said systemcontroller is operative to control flow of fluid by gravity head fromsaid selected one of said plural fluid input ports through said manifoldand out said vent port.
 6. The invention of claim 1, wherein said fluidmanifold includes a cassette having first and second mating housingportions, one of said housing portions defining a pumping chamber, andfurther includes a flexible diaphragm sandwiched therebetween defining apumping diaphragm adjacent said pumping chamber and a plurality of valvepads defining corresponding ones of said fluid input valves and saidoutput valve.
 7. The invention of claim 6, wherein said pumpingdiaphragm is dome shaped.
 8. The invention of claim 6, wherein saidpumping means includes a plurality of plungers individually mounted forreciprocating motion, and a first stepper motor driven cam mounted fordriving the plungers against and away from the corresponding input andoutput valve pads, and further includes a pumping piston mounted forreciprocating motion, and a second stepper motor driven cam mounted forcontrollably driving the pumping piston into and out of the pumpingchamber.
 9. An infusion system having plural fluid input ports and afluid output port, comprising:a fluid manifold having plural fluid inputvalves each connected to a corresponding one of said plural fluid inputports, a patient output valve connected to said fluid output port and influid communication with said plurality of fluid input valves, and meansin fluid communication with said plural fluid input valves and saidfluid output valve for pumping fluid from any input port through saidoutput port; a system controller having memory, a processor to providesystem I/O and pump control, and a pump processor slaved to said I/O andpump control processor via a communication link; means coupled to saidsystem controller for writing into said memory first data representativeof a desired course of infusion including at least one of time sequenceof fluid to be administered from any one or more of said fluid inputports, rate of fluid to be administered from corresponding ones of saidany one or more of said fluid input ports, and a duration of fluid to beadministered from corresponding ones of said any one or more of saidfluid input ports; a pressure transducer coupled to said systemcontroller and to said fluid manifold for providing second datarepresentative of the pressure in said fluid manifold; and means coupledto said system controller and to said fluid manifold and operative inresponse to said first and second data for selectively actuatingindividual ones of said fluid input valves in dependence on said firstdata to admit a selected fluid into said fluid manifold and for bothselectively actuating said output valve, and said pumping means independence on said first and second data.
 10. The invention of claim 9,wherein said writing means includes an operator interactive display andan operator keyboard having a plurality of function and data keys, saiddisplay and said keyboard being coupled to said system I/O and pumpcontrol processor.
 11. The invention of claim 9, wherein said pressuretransducer is operatively connected to said pump control processor, andsaid pump control processor is operative to read said pressuretransducer to obtain data representative of pressure of at least one ofcorresponding fluid input ports, of pressure in the fluid output port,and of air in the fluid manifold.